Abstract To determine the semantic importance of certain features has been a topic of interest for many semantic memory models. Diverse measures have been proposed in the last years. Semantic significance, the latest measure proposed by Montefinese and colleagues, is both sophisticated and comprehensive. Given the cultural and linguistic variability of semantic measures, this study presents values of significance and relative weight for the Spanish-speaking population corresponding to 400 concrete concepts. First, we presented data for both young and older adults. Second, we assessed the effect of significance on response times in two speeded feature verification tasks. Third, we compared significance values with the existing Italian significance norms. To evaluate the effect of significance to predict response times, two speeded verification tasks (Experiment 1 and 2) were carried out, selecting a total of a 130 concepts for analysis. In Experiment 1, subjects were presented with a feature followed by a concept, while in Experiment 2, the order of stimulus presentation was reversed (i.e., the concept was presented before the feature). An independent linear mixed model showed that significance was a good predictor of response latencies in Experiments 1 and 2. Moreover, results revealed a strong positive correlation between the Spanish and Italian significance values. Findings are discussed in terms of recent theories of semantic cognition.